Re: Why do we need congestion control?
Detlef Bosau <[email protected]>
| Newsgroups | gmane.network.end2end |
|---|---|
| Message-ID | <[email protected]> |
I could even extend my scenario with, say, PC 5 to PC 20 and TCP flows (bidirectional) from PC 5 to PC 7 etc. up to PC 18 to PC 20. In other words: I can increase the load. Hence, an individual flow's throughput / goodput will be decreased. Perhaps, this should be commonplaces here. However, I hardly find this in many papers or even less in simulations. (E.g. I never really understood/believed the Ethernet-simulation in the NS2.....) Am 10.04.2013 17:21, schrieb Detlef Bosau: > >>> Let me sketch a very simple scenario here. >>> >>> Think of four nodes, e.g. PC, attached to a simple coax Ethernet. >>> >>> PC 1 PC 2 PC >>> 3 PC 4 >>> | | | | >>> >>> ----------------------------------------------------------------------- >>> >>> Think of two bidirectional TCP flows here. >>> >>> One betwenn PC 1 and PC 3, the other between PC 2 and PC 4. >>> >>> >>> And now allow me to ask some questions. >>> >>> Q1: What do we want to achieve at all in this scenario? With >>> particular respect to the categories >>> - goodput >>> - throughput >>> - congestion avoidance >>> - fairness? >>> >>> Q2: Do we need VJCC in this scenario? >>> >>> Q3: Which of the goals stated in response to Q 1 are achieved? >>> >>> Q4: If goals are achieved, refer to Q3, what is the particular >>> contribution of VJCC here? >>> >>> This scenario is quite easy - and when I answered this questions for >>> myself, it became clear that I simply asked the wrong question when >>> I asked how many flows would fit into the Internet. >>> >>> To some degree, VJCC is a stroke of genius - while being a kludge at >>> the same time. >>> >>> So, I would like to ask: What are our goals? What do we achieve? Did >>> we achieve our goals? And is that what we achieve identical to our >>> intentions in the first? >>> >>> >>> >>> >>> >>> -- >>> ------------------------------------------------------------------ >>> Detlef Bosau >>> Galileistraße 30 >>> 70565 Stuttgart Tel.: +49 711 5208031 >>> mobile: +49 172 6819937 >>> Ich sehe nur den Klappentext zu Hetze-Rita: >>> >>> skype: detlef.bosau >>> ICQ: 566129673 >>> [email protected] http://www.detlef-bosau.de >>> > > -- ------------------------------------------------------------------ Detlef Bosau Galileistraße 30 70565 Stuttgart Tel.: +49 711 5208031 mobile: +49 172 6819937 skype: detlef.bosau ICQ: 566129673 [email protected] http://www.detlef-bosau.de